The present invention relates to a magnetic resonance imaging system utilizing magnetic resonance.
As described in, for example, Japanese Unexamined Patent Application Publication No. 2002-159465, a magnetic resonance imaging (MRI) system is a modality for imaging a region to be examined of a subject lying down in a static magnetic field space by utilizing magnetic resonance.
A magnet such as a permanent magnet is used to induce a static magnetic field. The magnet is borne by legs that are used to adjust the posture of the magnet and disposed on the floor in an installation site of an MRI system. For example, when the magnet is disposed in the installation site or if a gap is created between the floor and any of the legs because the floor has deformed time-sequentially, the posture of the magnet must be adjusted in order to correct the direction of the static magnetic field so that the direction of the static magnetic field will be aligned with a predetermined direction.
Conventionally, an adjustment sheet having a predetermined thickness is sandwiched between the floor and the leg in order to adjust the posture of the magnet. For the adjustment of the posture of the magnet, for example, a jack is used to cause the magnet and leg to float above the floor. The adjustment sheet is then sandwiched between the floor and the leg. Japanese Unexamined Patent Application Publication No. 2002-159465.
However, it is time-consuming to adjust the posture of the magnet using a special tool such as the jack. If the jack is made of a magnetic material such as iron, the jack is attracted to the magnet. This hinders the adjustment work. Furthermore, when the adjustment sheet is merely sandwiched between the floor and the leg, the vibration of the floor is propagated to the magnet through the portion of the placement surface of the floor under the leg. The vibration may adversely affect images resulting from magnetic resonance imaging.